The Excel CHIINV function returns the inverse of the right-tailed chi-squared distribution — the x value for a given right-tail probability. It is the legacy name of CHISQ.INV.RT, introduced in Excel 2010.
Syntax
| Argument | Description | |
|---|---|---|
probability | Required | A right-tail probability associated with the chi-squared distribution (between 0 and 1). |
deg_freedom | Required | The number of degrees of freedom (a positive integer). |
How to use it
CHIINV is the reverse of CHIDIST: give it a right-tail probability and it returns the chi-squared value (the critical value) that leaves that much area in the right tail.
This is the function that produces the critical values printed in chi-squared tables. Because it works with the right tail, the modern replacement is CHISQ.INV.RT — not the left-tailed CHISQ.INV.
Use CHISQ.INV.RT instead: =CHISQ.INV.RT(0.05,5) in Excel 2010+ returns the same critical value. Watch the naming: CHISQ.INV (no .RT) inverts the left tail.
Try it: interactive demo
Pick a CHIINV example to see the formula and its result.
Practice workbook
Frequently asked questions
What is the modern replacement for CHIINV?
CHISQ.INV.RT, added in Excel 2010 — the inverse of the right-tailed chi-squared distribution. =CHISQ.INV.RT(0.05,5) equals =CHIINV(0.05,5).What does CHIINV calculate?
Is CHIINV the inverse of CHIDIST?
Why use the right-tailed version?
CHISQ.INV.RT in modern workbooks; CHISQ.INV would give the left-tail value.Master functions like this in one day
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